Calamaria thanhi Ziegler & Le, 2005

Ziegler, Thomas, Hendrix, Ralf, Thanh, Vu Ngoc, Vogt, Martina, Forster, Bernhard & Kien, Dang Ngoc, 2007, The diversity of a snake community in a karst forest ecosystem in the central Truong Son, Vietnam, with an identification key, Zootaxa 1493, pp. 1-40 : 7-8

Calamaria thanhi Ziegler & Le, 2005 : Thanh's reed snake / Ran mai gam Thanh

Ziegler & Le (2005) described C. thanhi based on a single female specimen from adjacent to Phong Nha - Ke Bang National Park, Dan Hoa commune, Minh Hoa District, Quang Binh Province. Meanwhile a second specimen came to our attention, that was found during April 2005 close to the National Park's border during excavations in a secondary shrub area. Because the species was formerly only known from the heavily destroyed holotype, we herein provide first pictures of a better preserved and at the same time of the first male as well as also largest specimen of the barely known species ( Figures 6–9 ).

The new specimen (SVL 415, TaL 46, TL 461 mm), that is deposited in the Science Research Centre of the Phong Nha - Ke Bang National Park (SRC PNKB III '06-1), largely agrees with the holotype description in pattern and scalation (see Table 2 ), except for: 1) the rostral portion visible from above being somewhat shorter (1.5 mm) than the prefrontal suture (1.6 mm); 2) the left paraparietal being surrounded by seven instead of six shields and scales, as it is the case in the holotype; 3) the third supralabial being about half the size (instead ¾) of second; 4) the new specimen having 184 instead of 198 ventral scales and 28 instead of 21 divided subcaudals; 5) the number of dorsal scale rows is reduced to eight in the male specimen instead of six rows on tail opposite 8th subcaudal posterior to cloaca; 6) the ratio of tail to total length is 0.099 instead of 0.068 in the female holotype; 7) the male specimen bears five instead of four distinct beige to yellowish dorsal bands in the anterior two body thirds, followed by a sixth, but more vestigial light transversal band, that is only discernible from dorsal view; 8) the light dorsal bands subsequent to the first band follow each with distances of 3–5 cm in the male specimen (distances are extending posteriorly); 9) both yellowish markings on the dorsal tail base and on its end are better developed in the male specimen than it is the case in the female holotype, although both transversal bands do not completely encircle the dorsum; 10) the yellowish tail base bears only few tiny dark flecks in the male; 11) the underside of the head is not brownish-grey as it is the case in the female holotype but resembles the overall yellow venter coloration. We interpret the afore mentioned differences due to individual variation / sexual dimorphism.

In addition, we removed the inverted left hemipenis of the male specimen and dissected the thin organ in the inverted condition. Pedicel and truncus of the forked organ were smooth and without detectable spines, and both lobes were covered with a calyces ornamentation.

Figures

FIGURE 6. Thanh's reed snake (Calamaria thanhi), preserved male from Phong Nha - Ke Bang in dorsal view (SRC PNKB III ’ 06 - 1). Photo: Thomas Ziegler

FIGURE 7. Thanh's reed snake (Calamaria thanhi), preserved male from Phong Nha - Ke Bang in ventral view (SRC

FIGURE 8. Portrait of the preserved male Calamaria thanhi from Phong Nha - Ke Bang (SRC PNKB III ’ 06 - 1). Photo: Thomas Ziegler

FIGURE 9. Ventral view of the head of the preserved male Calamaria thanhi from Phong Nha - Ke Bang (SRC PNKB III ’ 06 - 1). Photo: Thomas Ziegler